If cos 45° - sec 30° = x, then value of x is

A

$${\frac{(1+\sqrt{2})}{{2}}}$$

B

$$\frac{(2\sqrt{2}-\sqrt{3})}{2}$$

C

$$\frac{(\sqrt{3}-2\sqrt{2})}{\sqrt{6}}$$

D

$$\frac{4}{\sqrt{3}}$$